Ex 8.1, 3 72% of 25 students are good in mathematics. How many are not good in mathematics?
Given, Total Students = 25
Percentage of Students good in mathematics = 72 %
Percentage of Students not good in mathematics = 100% − 72%
Percentage of Students not good in mathematics = 28%
Finding number of students not good in mathematics
Let number of Students not good in Mathematics = x
Percentage = (𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑠𝑡𝑢𝑑𝑒𝑛𝑡𝑠 𝑛𝑜𝑡 𝑔𝑜𝑜𝑑 𝑖𝑛 𝑚𝑎𝑡ℎ𝑒𝑚𝑎𝑡𝑖𝑐𝑠)/(𝑇𝑜𝑡𝑎𝑙 𝑠𝑡𝑢𝑑𝑒𝑛𝑡𝑠) × 100
28 = 𝑥/25×100
28 = 𝑥 × 4
28/4 = x
7 = x x = 7
∴ 7 Students are not good in mathematics